Method of forming memory cell

ABSTRACT

The present disclosure, in some embodiments, relates to an integrated chip. The integrated chip includes a lower interconnect disposed within a dielectric structure over a substrate. A memory device includes a data storage structure disposed between a bottom electrode and a top electrode. The bottom electrode is electrically coupled to the lower interconnect. A sidewall spacer includes an interior sidewall that continuously extends from along an outermost sidewall of the top electrode to below an outermost sidewall of the bottom electrode. The sidewall spacer further includes an outermost sidewall that extends from a bottom surface of the sidewall spacer to above a top of the bottom electrode.

REFERENCE TO RELATED APPLICATION

This Application is a Continuation of U.S. application Ser. No.16/579,757, filed on Sep. 23, 2019, the contents of which are herebyincorporated by reference in their entirety.

BACKGROUND

Many modern day electronic devices contain electronic memory configuredto store data. Electronic memory may be volatile memory or non-volatilememory. Volatile memory stores data when it is powered, whilenon-volatile memory is able to store data when power is removed.Magneto-resistive random-access memory (MRAM) is one promising candidatefor a next generation non-volatile memory technology. MRAM devices usemagnetic tunnel junctions (MTJs) to store data in a manner that allowsfor high speed data access and low power consumption.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 illustrates a cross-sectional view of some embodiments of anintegrated chip having a disclosed memory device formed by a processthat patterns a bottom electrode prior to forming sidewall spacers.

FIG. 2 illustrates a cross-sectional view of some embodiments of anintegrated chip having a disclosed memory device.

FIG. 3 illustrates a cross-sectional view of some embodiments of anintegrated chip having a disclosed memory device.

FIG. 4 illustrates a cross-sectional view of some embodiments of anintegrated chip having a disclosed memory device.

FIGS. 5-21 illustrate cross-sectional views of some embodiments of amethod of forming a plurality of MTJ devices, which defines bottomelectrodes of the MTJ devices prior to forming sidewall spacers alongsides of the MTJ devices.

FIG. 22 illustrates a flow diagram of some embodiments of a method 2200of forming a plurality of MTJ devices, which defines bottom electrodesof the MTJ devices prior to forming sidewall spacers along sides of theMTJ devices.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Magnetic tunnel junction (MTJ) devices comprise an MTJ verticallyarranged between lower and upper conductive electrodes. The MTJcomprises a pinned layer separated from a free layer by a tunnel barrierlayer. The magnetic orientation of the pinned layer is static (i.e.,fixed), while the magnetic orientation of the free layer is capable ofswitching between a parallel configuration and an anti-parallelconfiguration with respect to that of the pinned layer. The parallelconfiguration provides for a low resistive state that digitally storesdata as a first data state (e.g., a logical “1”). The anti-parallelconfiguration provides for a high resistive state that digitally storesdata as a second data state (e.g., a logical “0”).

Typically, MTJ devices are formed by depositing an MTJ stack over abottom electrode layer and subsequently depositing a top electrode layerover the MTJ stack. The top electrode layer and the MTJ stack are thenpatterned according to a first patterning process to define topelectrodes and a plurality of MTJs overlying the bottom electrode layer.A plurality of sidewall spacers and an etch stop layer are formed alongsidewalls of the plurality of MTJs. The one or more bottom electrodelayers are subsequently patterned according to the sidewall spacers todefine bottom electrodes below the plurality of MTJs. Top electrode viasare then formed over the top electrodes. The etch stop layer preventsthe top electrode vias from damaging the plurality of MTJs.

It has been appreciated that as a size of MTJ devices has shrunk, thesize between adjacent MTJ devices has also shrunk. As the size betweenadjacent MTJ devices shrinks, a distance between the sidewall spacers ofadjacent MTJ devices has become smaller (e.g., between approximately 1nm and 50 nm), making it increasingly difficult for the second etchingprocess to pattern the bottom electrode layer. Thinning the sidewallspacers can improve the ability of the second etching process to patternthe bottom electrode layer. However, thinning the sidewall spacers maycause the etch stop layer to be exposed and etched during the secondetching process. Etching the etch stop layer can lead to MTJ damageduring formation of a top electrode via and/or a redeposition of theetch stop material (e.g., aluminum-oxide) that can cause electricalleakage between the bottom electrodes of adjacent MTJ devices.

The present disclosure, in some embodiments, relates to a method offorming an MTJ device that eliminates the second patterning process usedto define bottom electrodes. Instead, the present disclosure uses asingle etching process to define a top electrode, an MTJ, and a bottomelectrode. A sidewall spacer is subsequently formed along sidewalls ofthe top electrode, the MTJ, and the bottom electrode followed by theformation of an etch stop layer over the sidewall spacer. By using asingle patterning process to define the top electrodes, the MTJs, andthe bottom electrodes, a size of a gap defining an etching area of abottom electrode layer is increased. Furthermore, forming the etch stoplayer after defining the bottom electrode prevents redeposition of theetch stop layer, thereby mitigating leakage between adjacent MTJdevices.

FIG. 1 illustrates a cross-sectional view of some embodiments of anintegrated chip 100 having a disclosed memory device formed by a processthat patterns a bottom electrode prior to forming sidewall spacers.

The integrated chip 100 comprises an access device 104 arranged over asubstrate 102. A dielectric structure 106 is also arranged over thesubstrate 102 and surrounds the access device 104. The dielectricstructure 106 comprises a lower dielectric structure 106 a surrounding aplurality of lower interconnect layers 108, which are electricallycoupled to the access device 104. In some embodiments, the access device104 may comprise a transistor device (e.g., a MOSFET, a bi-polarjunction transistor (BJT), a high electron mobility transistor (HEMT),or the like). In some embodiments, the plurality of lower interconnectlayers 108 comprise layers of conductive contacts 110, interconnectwires 112, and interconnect vias 114.

A plurality of memory devices 115 a-115 b are disposed within thedielectric structure 106 over the plurality of lower interconnect layers108. The plurality of memory devices 115 a-115 b comprise a data storagestructure 118 disposed between a bottom electrode 116 and a topelectrode 120. The data storage structure 118 is configured to storage adata state (e.g., corresponding to a logical “0” or a logical “1”). Invarious embodiments, the data storage structure 118 may comprise amagnetic tunnel junction, a high-k dielectric material, or the like.

One or more sidewall spacers 122 are arranged along sidewalls of theplurality of memory devices 115 a-115 b. The sidewall spacers 122continuously extend along outermost sidewalls 120 s of the top electrode120, outermost sidewalls 118 s of the data storage structure 118, andoutermost sidewalls 116 s of the bottom electrode 116 to below theoutermost sidewalls 116 s of the bottom electrode 116. For example, insome embodiments, the sidewall spacers 122 may extend a distance d₁below a bottom of the outermost sidewalls 116 s of the bottom electrode116. In some embodiments, the sidewall spacers 122 may extend along asidewall 106 s of the lower dielectric structure 106 a underlying alower surface 116L of the bottom electrode 116. The sidewall spacers 122have interior sidewalls that completely cover the outermost sidewalls116 s of the bottom electrode 116. In some embodiments, the interiorsidewalls of the sidewall spacers 122 may directly contact the outermostsidewalls 120 s of the top electrode 120, the outermost sidewalls 118 sof the data storage structure 118, and the outermost sidewalls 116 s ofthe bottom electrode 116. In some additional embodiments, the interiorsidewalls of the sidewall spacers 122 may further contact the sidewall106 s of the lower dielectric structure 106 a.

A top electrode via (TEVA) etch stop layer 124 is arranged along outersidewalls of the sidewall spacer 122 and an upper dielectric structure106 b is arranged on the TEVA etch stop layer 124. In some embodiments,the TEVA etch stop layer 124 may continuously extend from a sidewall ofa first memory device 115 a of the plurality of memory devices 115 a-115b to a sidewall of a second memory device 115 b of the plurality ofmemory devices 115 a-115 b. In such embodiments, the TEVA etch stoplayer 124 has a vertically extending segment and a horizontallyextending segment. The vertically extending segment is arranged along asidewall of the sidewall spacers 122 and protrudes outward from a topsurface of the horizontally extending segment to a horizontal line thatis parallel to and disposed along a top surface of the top electrode120.

The sidewall spacers 122 completely cover the outermost sidewalls 116 sof the bottom electrode 116 because the sidewall spacers 122 are formedafter performing one or more patterning processes that define the bottomelectrode 116. By forming the sidewall spacers 122 after the one or morepatterning processes, the bottom electrode 116 is able to be more easilypatterned at a small pitch (i.e., with a small space between adjacentmemory devices 115 a-115 b). Furthermore, because the TEVA etch stoplayer 124 is disposed over the sidewall spacers 122 it is also notsubjected to an etching process, thereby preventing redeposition ofmaterial from the TEVA etch stop layer 124 that could lead to electricalleakage between adjacent ones of the plurality of memory devices 115a-115 b.

FIG. 2 illustrates a cross-sectional view of additional some embodimentsof an integrated chip 200 having a disclosed memory device.

The integrated chip 200 comprises a dielectric structure 106 disposedover a substrate 102. The dielectric structure 106 comprises a pluralityof stacked inter-level dielectric (ILD) layers 107 a-107 d. In someembodiments, the plurality of stacked ILD layers 107 a-107 d maycomprise one or more of silicon dioxide, doped silicon dioxide (e.g.,carbon doped silicon dioxide), silicon oxynitride, borosilicate glass(BSG), phosphoric silicate glass (PSG), borophosphosilicate glass(BPSG), fluorinated silicate glass (FSG), or the like.

A plurality of lower interconnect layers 108 are arranged within aplurality of lower ILD layers 107 a-107 b of the dielectric structure106. In some embodiments, the plurality of lower interconnect layers 108comprise conductive contacts 110 and interconnect wires 112 respectivelysurrounded by one of the plurality of lower ILD layer 107 a-107 b. Insome additional embodiments (not shown), the plurality of lowerinterconnect layers 108 may further comprise conductive vias. In someembodiments, the interconnect wires 112 and/or conductive vias maycomprise a diffusion barrier layer (e.g., tantalum, titanium nitride, orthe like) surrounding a metal core (e.g., copper, tungsten, aluminum, orthe like).

A lower insulating structure 202, comprising one or more dielectricmaterials, is arranged over the plurality of lower ILD layers 107 a-107b. In various embodiments, the lower insulating structure 202 maycomprise an oxide (e.g., silicon oxide, silicon rich oxide, etc.), anitride (e.g., silicon nitride, silicon oxynitride, etc.), a carbide(e.g., silicon carbide, silicon oxycarbide, etc.), Tetraethylorthosilicate (TEOS), and/or the like. For example, in some embodiments,the lower insulating structure 202 may comprise a layer of siliconoxide, while in other embodiments the lower insulating structure 202 maycomprise a layer of silicon rich oxide disposed between layers ofsilicon carbide.

A plurality of MTJ devices 204 a-204 b are arranged within thedielectric structure 106 over the lower insulating structure 202. Theplurality of MTJ devices 204 a-204 b include a bottom electrode 116 thatis separated from a top electrode 120 by a magnetic tunnel junction(MTJ) 206. The bottom electrode 116 extends from over the lowerinsulating structure 202 to the plurality of lower interconnectstructures 108 under the lower insulating structure 202. In someembodiments, the bottom electrode 116 may comprise a liner (e.g., a gluelayer and/or a diffusion barrier layer) and an overlying conductivematerial. In some embodiments, the liner may comprise tantalum nitride,titanium nitride, or the like. In some embodiments, the conductivematerial may comprise titanium, tantalum, or the like. In someembodiments, the top electrode 120 may comprise one or more of titanium,tantalum, tungsten, tantalum nitride, titanium nitride, or the like.

In some embodiments, the MTJ 206 may comprise a pinned layer 208separated from a free layer 212 by a dielectric tunnel barrier 210. Thepinned layer 208 has a magnetization that is fixed, while the free layer212 has a magnetization that can be changed during operation (throughthe tunnel magnetoresistance (TMR) effect) to be either parallel (i.e.,a ‘P’ state) or anti-parallel (i.e., an ‘AP’ state) with respect to themagnetization of the pinned layer 208. A relationship between themagnetizations of the pinned layer 208 and the free layer 212 define aresistive state of the MTJ 206 and thereby enables the MTJ 206 to storea data state.

In some embodiments, the pinned layer 208 may comprise cobalt, iron,boron, nickel, ruthenium, iridium, platinum, or the like. In someembodiments, the dielectric tunnel barrier 210 may comprise magnesiumoxide, aluminum oxide, nickel oxide, gadolinium oxide, tantalum oxide,molybdenum oxide, titanium oxide, tungsten oxide, or the like. In someembodiments, the free layer 212 may comprise cobalt, iron, boron, ironcobalt, nickel cobalt, cobalt iron boride, iron boride, iron platinum,iron palladium, or the like.

One or more sidewall spacers 122 and a top electrode via (TEVA) etchstop layer 124 extend along sidewalls of the plurality of MTJ devices204 a-204 b. In various embodiments, the sidewalls spacers 122 maycomprise silicon nitride, a silicon dioxide (SiO₂), a nitride (e.g.,silicon oxy-nitride, silicon nitride, etc.), a carbide (e.g., siliconcarbide, etc.), or the like. In various embodiments, the TEVA etch stoplayer 124 may comprise one or more of silicon nitride (e.g., Si₃N₄), ametal-oxide (e.g., aluminum-oxide, hafnium-oxide, etc.), or the like. Anintermediate ILD layer 107 c is arranged over the TEVA etch stop layer124. In some embodiments, a top surface of the intermediate ILD layer107 c is substantially co-planar (e.g., co-planar within a tolerance ofa chemical mechanical planarization (CMP) process) with top surfaces ofthe TEVA etch stop layer 124 and/or the top electrode 120.

An upper interconnect structure 126 is disposed within an upper ILDstructure 107 d over the intermediate ILD layer 107 c. The upperinterconnect structure 126 contacts the top electrode 120. In someembodiments, the upper interconnect structure 126 may vertically extendbelow a top surface of the intermediate ILD layer 107 c. In some suchembodiments, the TEVA etch stop layer 124 may laterally separate theupper interconnect structure 126 from sidewalls of the top electrode120.

FIG. 3 illustrates a cross-sectional view of additional some embodimentsof an integrated chip 300 having a disclosed memory device.

The integrated chip 300 comprises one or more access devices 104disposed within a substrate 102. In some embodiments, the one or moreaccess devices 104 are laterally separated by way of an isolationstructure 302 disposed within the substrate 102. In some embodiments,the isolation structure 302 may comprise a shallow trench isolation(STI) structure comprising one or more dielectric materials disposedwithin a trench defined by sidewalls of the substrate 102.

A dielectric structure 106 is disposed over the substrate 102. Thedielectric structure 106 comprises a plurality of lower ILD layers 107a-107 b surrounding a plurality of lower interconnect layers 108. Insome embodiments, the plurality of lower ILD layers 107 a-107 b maycomprise a first ILD layer 107 a separated from a second ILD layer 107 bby way of a first etch stop layer 304 a. A second etch stop layer 304 bis disposed over the plurality of lower ILD layers 107 a-107 b. In someembodiments, the first etch stop layer 304 a and/or the second etch stoplayer 304 b may comprise a carbide, a nitride, or the like. A lowerinsulating structure 202 is arranged over the second etch stop layer 304b. The lower insulating structure 202 comprises first sidewalls directlyoverlying one of the plurality of lower interconnect layers 108. Thefirst sidewalls extend between a bottommost surface of the lowerinsulating structure 202 and a topmost surface of the lower insulatingstructure 202. The lower insulating structure 202 further comprisessecond sidewalls that extend between the topmost surface of the lowerinsulating structure 202 and an upper surface of the lower insulatingstructure 202.

A bottom electrode 116 is arranged within the opening and over thetopmost surface of the lower insulating structure 202. The bottomelectrode 116 comprises a top surface having a first width and a bottomsurface having a second width that is smaller than the first width. Thetop surface extends between outermost sidewalls 116 s of the bottomelectrode 116. The bottom electrode 116 extends through the lowerinsulating structure 202 and the second etch stop layer 304 b to one ofthe plurality of lower interconnect layers 108. In some embodiments, thelower insulating structure 202 may have a greater thickness directlybelow the bottom electrode 116 than laterally outside of the bottomelectrode 116.

An MTJ 206 is arranged over the top surface of the bottom electrode 116and a top electrode 120 is arranged over the MTJ 206. In someembodiments, the MTJ 206 may directly contact the top surface of thebottom electrode 116. In some embodiments, the top surface of the bottomelectrode 116 may have a width that is substantially equal to a width ofa bottom surface of the MTJ 206. In some embodiments, the bottomelectrode 116, the MTJ 206, and the top electrode 120 may have outermostsidewalls that are oriented at a first angle α with respect to ahorizontal line extending along the top surface of the bottom electrode116. In some embodiments, the first angle α may be an acute angle. Forexample, in some embodiments, the first angle α may be in a range ofbetween 80° and 90°.

One or more sidewall spacers 122 extend along the outermost sidewalls ofthe top electrode 120, the MTJ 206, and the bottom electrode 116. Insome embodiments, the sidewall spacers 122 may further extend along thesecond sidewalls of the lower insulating structure 202. In someembodiments, the sidewall spacers 122 may have a topmost surface that isrecessed below a topmost surface of the top electrode 120. In someembodiments, the sidewall spacers 122 may respectively have asubstantially constant width between a bottommost surface of thesidewall spacers 122 and a topmost surface of the sidewall spacers 122.In some embodiments, the sidewall spacers 122 may have a width in arange of between approximately 4 nanometers and approximately 20nanometers.

A top electrode via (TEVA) etch stop layer 124 is arranged over thesidewall spacer 122 and the lower insulating structure 202. The TEVAetch stop layer 124 vertically extends from over a top of the sidewallspacers 122 to below the topmost surface of the lower insulatingstructure 202. In some embodiments, a bottommost surface of the TEVAetch stop layer 124 is arranged along a horizontal plane that extendsthrough the first sidewalls of the lower insulating structure 202. Insome embodiments, the TEVA etch stop layer 124 directly contacts anupper surface of the lower insulating structure 202 at a position thatis between sidewalls of the sidewall spacers 122. In some embodiments,the TEVA etch stop layer 124 may extend to a position that is below abottom of the sidewall spacers 122. For example, in some embodiments,the TEVA etch stop layer 124 may extend below the bottom surface of thesidewall spacers 122 by a distance that is in a range of betweenapproximately 0 angstroms and approximately 200 angstroms. In someembodiments (not shown), the TEVA etch stop layer 124 may extend throughthe lower insulating structure 202 to contact the second etch stop layer304 b. In some embodiments, the TEVA etch stop layer 124 may have athickness in a range of between approximately 10 angstroms andapproximately 100 angstroms.

An intermediate ILD layer 107 c is over the TEVA etch stop layer 124. Insome embodiments, the intermediate ILD layer 107 c laterally extends fora distance d₂ between the sidewall spacers 122 surrounding a first MTJdevice 204 a and the sidewall spacers 122 surrounding a second MTJdevice 204 b. In some embodiments, distance d₂ is in a range of betweenapproximately 20 nanometers and approximately 150 nanometers. In someembodiments, the intermediate ILD layer 107 c directly contactssidewalls of the sidewall spacers 122. A third etch stop layer 304 c(e.g., comprising an oxide, a nitride, a carbide, or the like) is overthe intermediate ILD layer 107 c, and an upper ILD structure 107 d isover the third etch stop layer 304 c. An upper interconnect structure126 extends through the upper ILD structure 107 d and the third etchstop layer 304 c to contact the top electrode 120.

FIG. 4 illustrates a cross-sectional view of additional some embodimentsof an integrated chip 400 having a disclosed memory device.

The integrated chip 400 comprises a substrate 102 including an embeddedmemory region 402 and a logic region 404. Within the embedded memoryregion 402, a plurality of lower interconnect layers 108 are disposedwithin one or more lower ILD layers 107 a-107 b. The plurality of lowerinterconnect layers 108 are coupled between access devices 104 arrangedwithin the substrate 102 and MTJ devices 204 a-204 b arranged over alower insulating structure 202. The MTJ devices 204 a-204 b respectivelycomprise an MTJ 206 disposed between a bottom electrode 116 and a topelectrode 120. One or more sidewall spacers 122 are disposed alongopposing sides of the top electrode 120, the MTJ 206, the bottomelectrode 116, and the lower insulating structure 202. A TEVA etch stoplayer 124 is disposed on the sidewall spacers 122.

An intermediate ILD layer 107 c is disposed over the lower insulatingstructure 202 and surrounding the MTJ devices 204 a-204 b. An upperinterconnect structure 126 is disposed within an upper ILD structure 107d over the intermediate ILD layer 107 c. The upper interconnectstructure 126 may comprise a top electrode via 406 and an upperinterconnect wire 408 laterally extending past one or more sides of thetop electrode via 406. The top electrode via 406 couples the topelectrode 120 to the upper interconnect wire 408. The top electrode via406 is disposed directly on the top electrode 120. In some embodiments,the top electrode via 406 and the upper interconnect wire 408 maycomprise aluminum, copper, tungsten, or the like.

In some embodiments, the top electrode via 406 may vertically extendbelow a top of the intermediate ILD layer 107 c. In some suchembodiments, the top electrode via 406 may extend from over the topelectrode 120 to along sides of the TEVA etch stop layer 124. In suchembodiments, the top electrode via 406 may be laterally separated fromsidewalls of the top electrode 120 by way of the TEVA etch stop layer124.

Within the logic region 404, one or more additional interconnect layersare disposed within the dielectric structure 106. The one or moreadditional interconnect layers comprise a conductive contact 414, aninterconnect wire 416, and an interconnect via 418. The one or moreadditional interconnect layers are coupled to a logic device 412arranged within the substrate 102. In some embodiments, the logic device412 may comprise a transistor device (e.g., a MOSFET, a bi-polarjunction transistor (BJT), a high electron mobility transistor (HEMT),or the like).

In some embodiments, the dielectric structure 106 may comprise a logicILD layer 410 arranged over the one or more lower ILD layers 107 a-107 bwithin the logic region 404. The logic ILD layer 410 may comprise adifferent material than the intermediate ILD layer 107 c. In someembodiments, the logic ILD layer 410 may have a lower dielectricconstant than the intermediate ILD layer 107 c. For example, in someembodiments the logic ILD layer 410 may comprise a low-k dielectricmaterial (i.e., a dielectric material having a dielectric constant thatis less than approximately 3.9), while the intermediate ILD layer 107 cmay comprise an oxide. In some embodiments, the logic ILD layer 410 maycomprise a carbon doped silicon dioxide, silicon oxynitride,borosilicate glass (BSG), phosphoric silicate glass (PSG),borophosphosilicate glass (BPSG), fluorinated silicate glass (FSG), aporous dielectric material, or the like.

In some embodiments, the logic ILD layer 410 may have a sidewall thatcontacts an outermost sidewall of the TEVA etch stop layer 124 and asidewall of the lower insulating structure 202. In some suchembodiments, the lower insulating structure 202 may have a smallerheight within the logic region 404 than within the embedded memoryregion 402.

FIGS. 5-21 illustrate cross-sectional views 500-2100 of some embodimentsof a method of forming a plurality of MTJ devices by defining bottomelectrodes of the MTJ devices prior to forming sidewall spacers alongsides of the MTJ devices. Although FIGS. 5-21 are described in relationto a method, it will be appreciated that the structures disclosed inFIGS. 5-21 are not limited to such a method, but instead may stand aloneas structures independent of the method.

As shown in cross-sectional view 500 of FIG. 5, a substrate 102 isprovided. The substrate 102 comprises an embedded memory region 402 anda logic region 404. An access device 104 is formed within the embeddedmemory region 402 of the substrate 102 and a logic device 412 is formedwithin the logic region 404 of the substrate 102. In variousembodiments, the substrate 102 may be any type of semiconductor body(e.g., silicon, SiGe, SOI, etc.), such as a semiconductor wafer and/orone or more die on a wafer, as well as any other type of semiconductorand/or epitaxial layers, associated therewith. In some embodiments, theaccess device 104 and/or the logic device 412 may comprise a transistor.In some such embodiments, the access device 104 may be formed bydepositing a gate dielectric film and a gate electrode film over thesubstrate 102. The gate dielectric film and the gate electrode film aresubsequently patterned to form a gate dielectric 104 g and a gateelectrode 104 e. The substrate 102 may be subsequently implanted to forma source region 104 s and a drain region 104 d within the substrate 102on opposing sides of the gate electrode 104 e.

As shown in cross-sectional view 600 of FIG. 6, a plurality of lowerinterconnect layers 108 are formed within one or more lower inter-leveldielectric (ILD) layers 107 a-107 b over the substrate 102. In someembodiments, the one or more lower ILD layers 107 a-107 b may comprise afirst ILD layer 107 a and a second ILD layer 107 b separated by a firstetch stop layer 304 a. In some embodiments, the plurality of lowerinterconnect layers 108 may comprise a conductive contact 110 and aninterconnect wire 112. In some additional embodiments (not shown), theplurality of lower interconnect layers 108 may further comprise aninterconnect via. The plurality of lower interconnect layers 108 may beformed by forming one of the one or more lower ILD layers 107 a-107 bover the substrate 102 (e.g., an oxide, a low-k dielectric, or an ultralow-k dielectric), selectively etching the one or more lower ILD layers107 a-107 b to define a via hole and/or a trench within the ILD layer,forming a conductive material (e.g., copper, aluminum, etc.) within thevia hole and/or a trench, and performing a planarization process (e.g.,a chemical mechanical planarization process).

As shown in cross-sectional view 700 of FIG. 7, a second etch stop layer304 b is formed over the one or more lower ILD layers 107 a-107 b and alower insulating structure 202 is formed onto the second etch stop layer304 b. In some embodiments, the second etch stop layer 304 b maycomprise one or more of silicon-nitride, silicon-carbide, or the like.In some embodiments, the lower insulating structure 202 may comprise oneor more of an oxide, silicon-nitride, silicon-carbide, TEOS, or thelike. In some embodiments, the lower insulating structure 202 may beformed by a plurality of different deposition processes (e.g., physicalvapor deposition (PVD), chemical vapor deposition (CVD), PE-CVD, atomiclayer deposition (ALD), sputtering, etc.) to a thickness in a range ofbetween approximately 200 angstroms and approximately 300 angstroms.

As shown in cross-sectional view 800 of FIG. 8, the second etch stoplayer 304 b and the lower insulating structure 202 are selectivelypatterned to define a plurality of openings 802 extending through thesecond etch stop layer 304 b and the lower insulating structure 202. Theplurality of openings 802 expose one of the plurality of lowerinterconnect layers 108 (e.g., interconnect wire 112) underlying thelower insulating structure 202. In some embodiments, the second etchstop layer 304 b and the lower insulating structure 202 may beselectively patterned by exposing the second etch stop layer 304 b andthe lower insulating structure 202 to an etchant 804 according to apatterned masking layer 806 disposed on the lower insulating structure202.

As shown in cross-sectional view 900 of FIG. 9, one or more bottomelectrode layers 902 may be formed over the lower insulating structure202 and within the openings 802. The one or more bottom electrode layers902 extend through the lower insulating structure to one of theplurality of lower interconnect layers 108 (e.g., to interconnect wire112). In some embodiments, the one or more bottom electrode layers 902may be formed by depositing a liner followed by depositing a conductivematerial. In various embodiments, the liner may comprise a glue layerconfigured to increase adhesion between adjacent layers and/or adiffusion barrier layer configured to prevent diffusion between adjacentlayers. In some embodiments, the liner may comprise tantalum nitride,titanium nitride, or the like. In some embodiments, the conductivematerial may comprise tantalum, titanium, or the like. In someembodiments, a planarization process (e.g., a chemical mechanicalplanarization process) may be performed after depositing the conductivematerial, followed by the deposition of an additional conductivematerial onto the lower insulating layer and the conductive material. Inother embodiments, no planarization process is performed afterdepositing the conductive material.

As shown in cross-sectional view 1000 of FIG. 10, a MTJ stack 1002 isformed over the one or more bottom electrode layers 902. In someembodiments, the MTJ stack 1002 may comprise a lower ferromagnetic layer1004 formed over the one or more bottom electrode layers 902, atunneling barrier layer 1006 formed over the lower ferromagnetic layer1004, and an upper ferromagnetic electrode 1008 formed over thetunneling barrier layer 1006. One or more top electrode layers 1010(e.g., titanium, tantalum, titanium nitride, or the like) aresubsequently formed over the MTJ stack 1002.

As shown in cross-sectional view 1100 of FIG. 11, one or more patterningprocesses are performed to define a plurality of MTJ device stacks 1106a-1106 b. The one or more patterning processes selectively expose theone or more top electrode layers (1010 of FIG. 10), the MTJ stack (1002of FIG. 10), and the one or more bottom electrode layers (902 of FIG.10) to an etchant 1102 to define an MTJ 206 disposed between a bottomelectrode 116 and a top electrode structure 1108. The one or morepatterning processes may further etch the lower insulating structure 202to define sidewalls of the lower insulating structure under the bottomelectrode 116. Etching the lower insulating structure 202 causes thelower insulating structure 202 to have a smaller thickness laterallyoutside of the bottom electrode 116 than directly below the bottomelectrode 116. In some embodiments, the thickness of the lowerinsulating structure 202 directly below the bottom electrode 116 may bebetween approximately 2 and approximately 5 times larger than athickness of the lower insulating structure 202 outside of the bottomelectrode 116. In other embodiments, the thickness of the lowerinsulating structure 202 directly below the bottom electrode 116 may bemore than 5 times larger than a thickness of the lower insulatingstructure 202 outside of the bottom electrode 116.

In some embodiments, the one or more patterning processes may comprise asingle etching process (e.g., a continuous etching process using a sameetchant). In other embodiments, the one or more patterning processes maycomprise a plurality of etching processes (e.g., a plurality of discreteetching processes separated in time) performed in-situ within aprocessing chamber. In some embodiments, the one or more patterningprocesses may be performed with a masking layer (e.g., photoresistlayer, hardmask layer, or the like) in place over the top electrodelayer (1010 of FIG. 10).

As shown in cross-sectional view 1200 of FIG. 12, a spacer layer 1202 isformed over the lower insulating structure 202 and the plurality of MTJdevice stacks 1106 a-1106 b after completion of the one or morepatterning processes. The spacer layer 1202 is formed to contactsidewalls of the lower insulating structure 202, the bottom electrode116, the MTJ 206, and the top electrode structure 1108. In someembodiments, the spacer layer 1202 may be formed to a substantiallyconstant thickness in a range of between approximately 40 Angstroms andapproximately 400 Angstroms. In some embodiments, the spacer layer 1202may be formed using a deposition technique (e.g., PVD, CVD, PE-CVD, ALD,sputtering, etc.). In various embodiments, the spacer layer 1202 maycomprise silicon nitride, a silicon dioxide (SiO₂), silicon oxy-nitride(e.g., SiON), or the like.

As shown in cross-sectional view 1300 of FIG. 13, the spacer layer (1202of FIG. 12) is exposed to an etchant 1302, which removes the spacerlayer from horizontal surfaces. Removing the spacer layer fromhorizontal surfaces leaves a part of the spacer layer along opposingsides of the plurality of MTJ device stacks 1106 a-1106 b as thesidewall spacers 122. In some embodiments, etching the spacer layer maycause the sidewalls spacers 122 to be recessed below a top of the topelectrode structure 1108. In some embodiments, the etchant 1302 maycomprise a dry etchant.

As shown in cross-sectional view 1400 of FIG. 14, a top electrode via(TEVA) etch stop layer 124 is formed over the sidewall spacers 122, thetop electrode structure 1108, and the lower insulating structure 202. Insome embodiments, the TEVA etch stop layer 124 may comprise ametal-oxide (e.g., aluminum-oxide, hafnium-oxide, etc.), siliconnitride, or the like. In some embodiments, the TEVA etch stop layer 124may be formed by way of a deposition process (e.g., PVD, CVD, PE-CVD,ALD, or the like) to a thickness in a range of between approximately 1nanometer and approximately 10 nanometers.

As shown in cross-sectional view 1500 of FIG. 15, an intermediate ILDlayer 107 c is formed over the TEVA etch stop layer 124. Theintermediate ILD layer 107 c is formed to completely cover a top of theTEVA etch stop layer 124. In some embodiments, the intermediate ILDlayer 107 c may be formed by a deposition process (e.g., PVD, CVD,PE-CVD, ALD, or the like). In various embodiments, the intermediate ILDlayer 107 c may comprise an oxide (e.g., silicon dioxide) or the like.

As shown in cross-sectional view 1600 of FIG. 16, a planarizationprocess is performed (along line 1602) to remove parts of theintermediate ILD layer 107 c, the TEVA etch stop layer 124, and the topelectrode structure (1108 of FIG. 15). By removing a part of the topelectrode structure, the planarization process defines a plurality ofMTJ devices 204 a-204 b respectively having a top electrode 120 over theMTJ 206. In some embodiments, the planarization process may comprise achemical mechanical planarization (CMP) process.

As shown in cross-sectional view 1700 of FIG. 17, the intermediate ILDlayer 107 c, the TEVA etch stop layer 124, and a part of the lowerinsulating structure 202 are removed from within the logic region 404.In some embodiments, a masking layer 1702 is formed over theintermediate ILD layer 107 c within the embedded memory region 402. Theintermediate ILD layer 107 c is subsequently exposed to an etchant 1704that etches the intermediate ILD layer 107 c according to the maskinglayer 1702 to remove the intermediate ILD layer 107 c from within thelogic region 404. In some embodiments (not shown), the etching processmay cause the intermediate ILD layer 107 c to have an angled sidewallfacing the logic region 404. In various embodiments, the masking layer1702 may comprise one or more of silicon carbide, silicon nitride, orthe like.

As shown in cross-sectional view 1800 of FIG. 18, a logic ILD layer 410is formed over the intermediate ILD layer 107 c within the embeddedmemory region 402 and over the lower insulating structure 202 within thelogic region 404. In some embodiments, the logic ILD layer 410 may bedeposited by a deposition process (e.g., PVD, CVD, PE-CVD, ALD, or thelike). In various embodiments, the logic ILD layer 410 may comprise adifferent material than the intermediate ILD layer 107 c. In someembodiments, wherein spaces between adjacent interconnect structures inthe logic region 404 are larger than spaces between adjacent MTJ devicesin the embedded memory region 402, the logic ILD layer 410 may comprisea material that has a lower dielectric constant and worse gap fillcapabilities than the intermediate ILD layer 107 c. In some embodiments,the logic ILD layer 410 may comprise silicon dioxide, carbon dopedsilicon dioxide, silicon oxynitride, borosilicate glass (BSG),phosphoric silicate glass (PSG), borophosphosilicate glass (BPSG),fluorinated silicate glass (FSG), a porous dielectric material, or thelike.

As shown in cross-sectional view 1900 of FIG. 19, one or more additionalinterconnect layers are formed within the logic ILD layer 410. In someembodiments, the one or more additional interconnect layers may comprisean interconnect via 418 and an interconnect wire 416. The one or moreadditional interconnect layers may be formed by selectively etching thelogic ILD layer 410 to define a via hole and/or a trench within thelogic ILD layer 410, forming a conductive material (e.g., copper,aluminum, etc.) within the via hole and/or a trench, and performing aplanarization process (e.g., a chemical mechanical planarizationprocess). In some embodiments, the planarization process removes thelogic ILD layer 410 from over the intermediate ILD layer 107 c. In someembodiments, the planarization process may comprise a chemicalmechanical planarization (CMP) process.

As shown in cross-sectional view 2000 of FIG. 20, an upper ILD structure107 d is formed over the intermediate ILD layer 107 c within theembedded memory region 402 and over the logic ILD layer 410 within thelogic region 404. In some embodiments, a third etch stop layer 304 c maybe formed onto the intermediate ILD layer 107 c and the logic ILD layer410 prior to the formation of the upper ILD structure 107 d. In someembodiments, the upper ILD structure 107 d may be deposited by adeposition process (e.g., PVD, CVD, PE-CVD, ALD, or the like). In someembodiments, the upper ILD structure 107 d may comprise silicon dioxide,carbon doped silicon dioxide, silicon oxynitride, borosilicate glass(BSG), phosphoric silicate glass (PSG), borophosphosilicate glass(BPSG), fluorinated silicate glass (FSG), a porous dielectric material,or the like.

As shown in cross-sectional view 2100 of FIG. 21, an upper interconnectstructure 126 is formed within the upper ILD structure 107 d. In someembodiments, the upper interconnect structure 126 may comprise a topelectrode via 406 disposed on the top electrode 120 of one of the MTJdevices 204 a-204 b, and an upper interconnect wire 408 vertically overthe top electrode via 406 and laterally extending past one or more sidesof the top electrode via 406. In some embodiments, the upperinterconnect structure 126 may be formed by etching the upper ILDstructure 107 d to form a via hole and/or trench, which is filled with aconductive material (e.g., tungsten, copper, and/or aluminum). Achemical mechanical planarization (CMP) process is subsequentlyperformed to remove excess of the conductive material from over theupper ILD structure 107 d.

FIG. 22 illustrates a flow diagram of some embodiments of a method 2200of forming a plurality of MTJ devices by defining bottom electrodes ofthe MTJ devices prior to forming sidewall spacers along sides of the MTJdevices.

While method 2200 is illustrated and described herein as a series ofacts or events, it will be appreciated that the illustrated ordering ofsuch acts or events are not to be interpreted in a limiting sense. Forexample, some acts may occur in different orders and/or concurrentlywith other acts or events apart from those illustrated and/or describedherein. In addition, not all illustrated acts may be required toimplement one or more aspects or embodiments of the description herein.Further, one or more of the acts depicted herein may be carried out inone or more separate acts and/or phases.

At 2202, an access device is formed within an embedded memory region ofa substrate. FIG. 5 illustrates a cross-sectional view 500 of someembodiments corresponding to act 2202.

At 2204, lower interconnect layers are formed within one or more lowerILD layers over the substrate. In some embodiments, the lowerinterconnect layers are coupled to the access device. FIG. 6 illustratesa cross-sectional view 600 of some embodiments corresponding to act2204.

At 2206, a lower insulating structure is formed over the one or morelower ILD layers. FIGS. 7-8 illustrate cross-sectional views 700-800 ofsome embodiments corresponding to act 2206.

At 2208, a stack of MTJ device layers is formed over the lowerinsulating structure. In some embodiments, the stack of MTJ devicelayers may be formed according to acts 2210-2214.

At 2210, one or more bottom electrode layers are formed over the lowerinsulating structure and within openings extending through the lowerinsulating structure to the lower interconnect layers. FIG. 9illustrates a cross-sectional view 900 of some embodiments correspondingto act 2210.

At 2212, an MTJ stack is formed over the one or more bottom electrodelayers. FIG. 10 illustrates a cross-sectional view 1000 of someembodiments corresponding to act 2212.

At 2214, one or more top electrode layers are formed over the MTJ stack.FIG. 10 illustrates a cross-sectional view 1000 of some embodimentscorresponding to act 2214.

At 2216, one or more etching processes are performed on the stack of MTJdevice layers to etch the one or more top electrode layers, the MTJstack, and the bottom electrode structure and to define a plurality ofMTJ device stacks respectively having a MTJ disposed between a bottomelectrode and a top electrode structure. FIG. 11 illustrates across-sectional view 1100 of some embodiments corresponding to act 2216.

At 2218, one or more sidewall spacers are formed along sidewalls of theMTJ device stacks after the one or more etching processes are complete.In some embodiments, the sidewall spacers may extend to a sidewall ofthe lower insulating layer. FIGS. 12-13 illustrate cross-sectional views1200-1300 of some embodiments corresponding to act 2218.

At 2220, a top electrode via (TEVA) etch stop layer is formed over thesidewall spacers. FIG. 14 illustrates a cross-sectional view 1400 ofsome embodiments corresponding to act 2220.

At 2222, an intermediate ILD layer is formed over the TEVA etch stoplayer. FIG. 15 illustrates a cross-sectional view 1500 of someembodiments corresponding to act 2222.

At 2224, a planarization process is performed to remove parts of theintermediate ILD layer and the TEVA etch stop layer, and to expose a topsurface of a top electrode. FIG. 16 illustrates a cross-sectional view1600 of some embodiments corresponding to act 2224.

At 2226, an upper interconnect structure is formed onto the topelectrode. FIGS. 20-21 illustrate cross-sectional views 2000-2100 ofsome embodiments corresponding to act 2226.

Accordingly, in some embodiments, the present disclosure relates to amethod of forming an MTJ device that uses a single etching process todefine a top electrode, an MTJ, and a bottom electrode. By using asingle patterning process to define the MTJ device, a gap defining anetching area of a bottom electrode layer is increased.

In some embodiments, the present disclosure relates to an integratedchip. The integrated chip includes a dielectric structure disposed overa substrate; a plurality of lower interconnect layers disposed withinthe dielectric structure; a memory device having a data storagestructure disposed between a bottom electrode and a top electrode, thebottom electrode electrically coupled to the plurality of lowerinterconnect layers; and a sidewall spacer continuously extending froman outermost sidewall of the data storage structure to below anoutermost sidewall of the bottom electrode. In some embodiments, thesidewall spacer continuously extends from the outermost sidewall of thedata storage structure to an outermost sidewall of the top electrode. Insome embodiments, the sidewall spacer has an interior sidewallcontacting the outermost sidewall of the data storage structure and theoutermost sidewall of the bottom electrode. In some embodiments, thedielectric structure includes a plurality of lower inter-leveldielectric (ILD) layers disposed over the substrate and surrounding theplurality of lower interconnect layers, an etch stop layer disposed overthe plurality of lower ILD layers, and a lower insulating structuredisposed over the etch stop layer, the bottom electrode extending fromover the lower insulating structure to one of the plurality of lowerinterconnect layers. In some embodiments, the lower insulating structurehas a greater thickness directly below the bottom electrode thanlaterally outside of the bottom electrode. In some embodiments, theinterior sidewall of the sidewall spacer further contacts a sidewall ofthe lower insulating structure. In some embodiments, the integrated chipfurther includes a top electrode via etch stop layer that continuouslyextends from a sidewall of the sidewall spacer to an outermost sidewallof the top electrode. In some embodiments, the integrated chip furtherincludes a second memory device having a second data storage structuredisposed between a second bottom electrode and a second top electrode,the top electrode via etch stop layer continuously extending from asidewall of the memory device to a sidewall of the second memory device.In some embodiments, the integrated chip further includes an upperinterconnect structure disposed on the top electrode, the upperinterconnect structure extending from over top electrode to along sidesof the top electrode via etch stop layer. In some embodiments, ahorizontal line extending along a bottom of the top electrode via etchstop layer also extends through sidewalls of the lower insulatingstructure, the horizontal line is parallel to a bottom surface of thebottom electrode. In some embodiments, the bottom electrode has a bottomsurface with a first width and a top surface with a second width that islarger than the first width; and the sidewall spacer has a bottomsurface disposed along a horizontal line that is between the top surfaceand the bottom surface.

In other embodiments, the present disclosure relates to an integratedchip. The integrated chip includes a lower inter-level dielectric (ILD)layer disposed over a substrate; a lower interconnect layer disposedwithin the lower ILD layer; a lower insulating structure disposed overthe lower ILD layer; a magnetic tunnel junction (MTJ) device having anMTJ disposed between a bottom electrode and a top electrode, the bottomelectrode arranged on the lower interconnect layer and extending throughthe lower insulating structure; and a top electrode via etch stop layercontinuously extending from an outermost sidewall of the top electrodeto below an outermost sidewall of the bottom electrode. In someembodiments, the integrated chip further includes a sidewall spacercompletely covering the outermost sidewall of the bottom electrode andan outermost sidewall of the MTJ. In some embodiments, the sidewallspacer contacts the outermost sidewall of the MTJ, the outermostsidewall of the bottom electrode, and a sidewall of the lower insulatingstructure. In some embodiments, the top electrode via etch stop layerhas a vertically extending segment protruding outward from a top surfaceof a horizontally extending segment, the vertically extending segmentextending along a sidewall of the sidewall spacer to a horizontal linethat is parallel to and disposed along a top surface of the topelectrode. In some embodiments, the integrated chip further includes anintermediate ILD layer laterally surrounding the MTJ device, the topelectrode via etch stop layer having an upper surface facing away fromthe substrate and contacting a lower surface of the intermediate ILDlayer. In some embodiments, the integrated chip further includes anintermediate ILD layer laterally surrounding the MTJ device andlaterally separated from the MTJ device by way of the top electrode viaetch stop layer, the top electrode via etch stop layer continuouslyextending from directly below the intermediate ILD layer to a horizontalline that is parallel to and disposed along a top surface of the topelectrode.

In yet other embodiments, the present disclosure relates to a method offorming an integrated chip. The method includes forming a lowerinterconnect layer within a lower inter-level dielectric (ILD) layerover a substrate; forming one or more bottom electrode layers over thelower interconnect layer; forming a magnetic tunnel junction (MTJ) stackover the one or more bottom electrode layers; forming one or more topelectrode layers over the MTJ stack; performing one or more etchingprocesses to selectively pattern the one or more top electrode layers,the MTJ stack, and the one or more bottom electrode layers, and todefine a top electrode structure, an MTJ, and a bottom electrode; andforming a sidewall spacer along outermost sidewalls of the MTJ and thebottom electrode after the one or more etching processes are complete.In some embodiments, the method further includes forming a lowerinsulating structure over the lower ILD layer; etching the lowerinsulating structure to form first sidewalls of the lower insulatingstructure that define opening that exposes the lower interconnect layer;forming the one or more bottom electrode layers within the opening andover the lower insulating structure; and forming the sidewall spaceralong second sidewalls of the lower insulating structure after the oneor more etching processes are complete. In some embodiments, the methodfurther includes forming a top electrode via etch stop layer onto avertically extending surface of the sidewall spacer and onto ahorizontally extending surface of the lower insulating structure;forming an upper ILD layer over the top electrode via etch stop layer;and performing a planarization process to remove part of the upper ILDlayer, the top electrode via etch stop layer, and the top electrodestructure.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. An integrated chip, comprising: a lowerinterconnect disposed within a dielectric structure over a substrate; amemory device comprising a data storage structure disposed between abottom electrode and a top electrode, wherein the bottom electrode iselectrically coupled to the lower interconnect; a sidewall spacercomprising an interior sidewall that continuously extends from along anoutermost sidewall of the top electrode to below an outermost sidewallof the bottom electrode; and wherein the sidewall spacer furthercomprises an outermost sidewall that extends from a bottom surface ofthe sidewall spacer to above a top of the bottom electrode.
 2. Theintegrated chip of claim 1, further comprising: an etch stop layerlaterally contacting both the sidewall spacer and the outermost sidewallof the top electrode.
 3. The integrated chip of claim 1, furthercomprising: an etch stop layer disposed on the sidewall spacer, whereinthe etch stop layer has outer surfaces facing away from the memorydevice and intersecting at a corner that is directly over the sidewallspacer.
 4. The integrated chip of claim 1, wherein the interior sidewallof the sidewall spacer faces the memory device and extends between thebottom surface of the sidewall spacer and a top of the sidewall spacer.5. The integrated chip of claim 1, further comprising: an etch stoplayer disposed on the sidewall spacer, wherein the etch stop layer andthe top electrode have uppermost surfaces that are substantiallyco-planar.
 6. The integrated chip of claim 1, further comprising: anetch stop layer disposed on the sidewall spacer, wherein the etch stoplayer has a horizontally extending surface directly over the sidewallspacer and a vertically extending surface protruding outward from a topof the horizontally extending surface.
 7. The integrated chip of claim1, further comprising: an etch stop layer disposed on the sidewallspacer and comprising a horizontally extending surface directly over thesidewall spacer, the horizontally extending surface coupled between anunderlying vertically extending surface of the etch stop layer and anoverlying vertically extending surface of the etch stop layer.
 8. Anintegrated chip, comprising: a lower interconnect disposed within alower inter-level dielectric (ILD) layer over a substrate; a lowerinsulating structure disposed over the lower ILD layer; a memory devicecomprising a data storage structure disposed between a bottom electrodeand a top electrode, wherein the bottom electrode is arranged on thelower interconnect and extends through the lower insulating structure; asidewall spacer continuously extending from along an outermost sidewallof the data storage structure to below an outermost sidewall of thebottom electrode; and an etch stop layer disposed over the sidewallspacer and comprising a horizontally extending surface that is below atop of the etch stop layer and that is directly over the sidewallspacer.
 9. The integrated chip of claim 8, further comprising: an upperILD layer laterally surrounding the etch stop layer, wherein animaginary vertical line that is perpendicular to an upper surface of thebottom electrode vertically extends through the sidewall spacer, theetch stop layer, and the upper ILD layer.
 10. The integrated chip ofclaim 8, wherein the etch stop layer is aluminum oxide.
 11. Theintegrated chip of claim 8, wherein the etch stop layer continuouslyextends from along an outermost sidewall of the top electrode to belowthe outermost sidewall of the bottom electrode.
 12. The integrated chipof claim 8, wherein the etch stop layer has a thickness that is in arange of between approximately 10 angstroms and approximately 100angstroms.
 13. The integrated chip of claim 8, wherein the etch stoplayer has a first thickness and the sidewall spacer has a secondthickness that is greater than the first thickness.
 14. An integratedchip, comprising: a lower interconnect disposed within a lowerinter-level dielectric (ILD) layer over a substrate; a lower insulatingstructure arranged over the lower ILD layer; a bottom electrodeelectrically coupled to the lower interconnect and extending through thelower insulating structure; a data storage structure disposed on thebottom electrode; a top electrode disposed on the data storagestructure; a sidewall spacer continuously extending along sidewalls ofthe data storage structure, the bottom electrode, and the lowerinsulating structure; an etch stop layer continuously extending along anouter sidewall of the sidewall spacer; an upper ILD layer surroundingthe etch stop layer; and an upper interconnect continuously extendingfrom over the top electrode to within the upper ILD layer and along oneor more sidewalls the etch stop layer.
 15. The integrated chip of claim14, wherein the upper interconnect comprises a horizontally extendingsurface over the sidewall spacer and a sidewall extending outward fromthe horizontally extending surface at a location that is directly overthe sidewall spacer.
 16. The integrated chip of claim 14, wherein theetch stop layer separates a sidewall of the upper interconnect from asidewall of the top electrode.
 17. The integrated chip of claim 14,wherein the etch stop layer is directly between the upper interconnectand the sidewall spacer.
 18. The integrated chip of claim 14, whereinthe etch stop layer has an outer sidewall facing away from the topelectrode, the outer sidewall of the etch stop layer contacting theupper interconnect and the upper ILD layer.
 19. The integrated chip ofclaim 14, wherein the etch stop layer and the upper ILD layer haveuppermost surfaces that are substantially co-planar.
 20. The integratedchip of claim 14, wherein the etch stop layer has an uppermost surfacethat is coupled to a sidewall that is completely confined above thesidewall spacer.